On Microscopic Insights into Metal Cluster Fragmentation

Abstract

Metal cluster fragmentation has been a topic of intense experimental activity for many years [1,2,3]. In many early investigations the excitation process, for example through a low fluence nanosecond laser, leads to an excited cluster in which both electronic and ionic degrees of freedom were simultaneously excited. The such produced highly charged cluster was thus already at thermal equilibrium and its further deexcitation proceeded by evaporation, fission or fragmentation, and could be accessed to by statistical concepts [4]. With the advent of more instantaneous excitation processes, namely at a time scale typical of electronic characteristic times, the situation is somewhat different as excitation and initial ionization proceed at once, thus placing the charged cluster in a definitively far from equilibrium state. The understanding of the further evolution of the system thus requires a proper description of the electronic degrees of freedom and of their coupling to ionic o nes.